A Winnipeg police officer accused of kicking a man in custody so hard that he required emergency surgery was acquitted of all charges on Monday after a lengthy legal process.

Const. Ryan Law was charged with aggravated assault after Henry Lavallee reported a bad injury while in a holding cell at the Public Safety Building in November 2008.

Lavallee was rushed to hospital for emergency surgery and testimony from a doctor at the trial indicated he nearly died.

Law was charged in June 2009, but the trial did not begin until November 2012.

On Monday, Law was acquitted.

The judge presiding over the trial said the Crown did not prove its case. One of the factors the judge mentioned in the written decision in the case was the timing of the injury.

The judge favoured the testimony of a doctor who said the injury likely happened before Lavallee was taken in custody, however another doctor did testify she believed the injury could have happened while Lavallee was in his cell.

The decision also indicated the judge found Law's testimony to be credible and found Lavallee's testimony "difficult to accept" and "not credible in nature."

Law is at least the tenth Manitoba police officer charged with a criminal offence to be acquitted in the last five years.